A probe mark is left on bond pads after chip probe (CP) sorting. This probe mark will be enlarged during the integrated circuit (IC) assembly wafer die-sawing due to a so-called “Galvanic effect,” i.e. an electrochemical reaction on the bond pad during the die-sawing. This may: expose the bond pad under-layer which has a great impact on the subsequent wire bonding process; degrade the wire bond integrity; and lead to assembly yield loss.
This probe mark enlargement is especially so and more serious for the larger 12-inch wafers since longer die-sawing is required for the larger area of the 12 inch-wafer. To minimize this exacerbated problem for the larger 12-inch wafers conventionally, attempts are made to shorten the 12-inch wafer die-saw process time although sometimes this is not possible.
U.S. Pat. No. 6,335,224 B1 to Peterson et al. discloses protection of microelectronic devices during packaging.
U.S. Pat. No. 6,297,561 B1 to Liu et al. discloses a semiconductor chip.
U.S. Pat. No. 6,251,694 B1 to Liu et al. discloses a method of testing and packaging a semiconductor chip.